exchanger



Feb. 12, 1963 R. E. JAPHET 3,077,086

FORCE FEED HEAT PUMP SYSTEM MMM HMT

Feb. 12, 1963 R. E. JAPHET 3,077,086

FORCE FEED HEAT PUMP SYSTEM Filed May 2, 1961 4 Sheets-Sheet 2 lo OUTDOOR HEAT 3 f'. EXCHANG-ER I2 's cooLED GAS Y 40F. 4f 4s Psx@ 35 33 44 4g PL SUPERHE `rev INDNR HEAT 32 EXC HANGER /19 G /6 L14) /B" I8 '-"I H.P.r=L.oA-r REG. i U7) 7 5 9 52 AccuMuLAroR t (zo) HUT @As s 2ool Z50 PSIG 4Z A|R PUMP n51 (40) F 3 I0 onaook HEAT ,3

Excl-MANGER DEFROST CYCLE l UI) I4 f I 30F.' l::*\I2 /ls COLD WATER INUOSRF U wArERo Ltor: 26 35 F. 33 35 BO PSIG 7s Pslcr L E w 46 `25 GAS a Llqulo INDooN-r oop.

ExcH 44 j L (24) 7s Psl 34.

G 3 y Y E# I9 -29 32 ,s l 43 4s H.P. FLOAT REG. I (I7 2| ACCUMULATOR FI 4 9o PslG (4o) lNTERMEDlm-E RICHARD E. JIDHET COOLING CYCLE INVENTOR.

PARALLEL FLOW i' M BY Feb. l2, 1963 R. E. JAPHET 3,077,086

FORCE FEED HEAT PUMP SYSTEM Filed May 2, 1961 4 Sheets-Sheet 3 ouv-Doue HEAT I3 Exc-.HANGER f G3 5 Sz la H.P- FLQAT REG- n7x (I7) '7 8 9 52 2 2| AccuMuLNraR 22 53 CoMPRESSOR LIQUID 4| 1) 4o F. '\5 o Psls sl/H; y

42 aga?, PUMP 9 Ps G (4) FIG. 6

,NTERMEDWE RICHARD E. JAPHET INV EN TUR.

COOLING CYCLE s ERIES FLow eb. 12, 1963 R. E. JAPHET 3,077,086

FORCE FEED HEAT PUMP SYSTEM Filed May 2, 1961 4 Sheets-Sheet 4 ouroooR HEAT Y EXCHANGER PUMP (4o) FIG. 7

WITH Low PRESSURE SEPARATION MEANS RICHARD E. TAPHET IN V EN TOR.

United States Patent Otice E'i'd Patented Feh. l2, 1953 The invention relates generally to heat pumps and more particularly to a heat pump embodying a force feed circulation cycle.

The use of heat pumps particularly for .air conditioning has become an accepted industrial, commercial and residential practice.

Conventional heat pump systems in use today whether of the flooded or direct expansion type have the compressors and the heat exchangers for the heat pump system connected for series iiow and the heat pump systems are characterized by the fact that operation depends on reversal of the direction of flow of the refrigerant lluid in the heat exchangers and the system coupled with a change in function of the heat exchangers to obtain the desired heating and cooling.

Conventional heat pumps of the Hooded type and direct expansion type have many limitations, restrictions and operational problems.

For example, iu Hooded type heat pumps, the surge drum height is a critical factor because the operation of the system is by gravity circulation.

Other difficulties of the ilooded type heat pump system are as follows:

(l) Float controls are required on each of the heat exchangers.

(2) Oil recovery means including an oil separator are :necessary from each of the heat exchangers.

(3) The heat transfer rate is relatively low so that large heat exchangers are required.

(4) Overcompiication of the controls to regulate the operation of the system results in unrealiable automation which is subject to continuous mechanical failure.

(5) Because flooded systems require a large number of liuxiliary traps, recovery tanks, etc. for elicient and effective operation, the commercial cost of manufacturing lthere units is increased.

(i5) The defrost cycle of such flooded type heat pump system robs heat from the media being heated or uses external mechanical or electrical mechanisms associated with the heat pump to effect the defrosting needed.

Similarly, in direct expansion heat pump systems:

l) The heat exchangers must be extremely large because greater heat transfer service is required due to the poor heat transfer coeicient.

(.2) Larger heat exchangers are required to provide the superheat needed to obtain the desired operation in the respective heat exchangers.

(3) Each heat exchanger requires its own expansion valve arrangements which necessitates a duplication of controls for each direction of flow.

(4) There are extremely difficult expansion valve adjustment problems with outdoor Weather changes.

(5) The system is subject to slugging during start-up and the defrost cycle.

(6) Due to the fact that the gas refrigerant has entrained oil, oil recovery is complicated by critical gas velocities during unloading of the compressor.

(7) Direct expansion systems normally employ a special four (4) way reversing valve.

it is also well known in the conventional type heat pump of either the flooded or direct expansion type, particularly when used for heating and cooling, that there are intermediate periods of temperature and humidity where the systems operate inefliciently.

The present inventeion overcomes these and other problems by providing an improved simplified heat pump having a cooling, heating and intermediate cycle wherein` a compressor functions in a condensing or high pressure side cycle and a pump functions in `an evaporating or low pressure side cycle which cycles are relatively independent but coact by means of a common accumulator or the like separating means.

Thus the present invention contemplates Aan improved heat pump which includes, a compressor disposed to selectively pass hot compressed gaseous refrigerant from the compressor to the inlet of either a first or a second heat exchanger which heat exchangers in turn have theirk outlets in communication with a common separating means from which the compressor takes its suction, andA a pump circulation cycle to coact with the compressor for delivering relatively cold liquid Vrefrigerant under pressure from the separating means to the inlet of that heat exchanger not receiving hot compressed gaseous refrigerant for the heating or cooling cycle; or to operateindependently and without the compressor to deliver relatively cold liquid refrigerant from the separating means and to the heat exchangers either in parallel or series during the intermediate cycle.

The present invention also contemplates a heat pumpsystem including a compression cycle and pump circulation cycle wherein a relatively simple recovery means is provided for dissolved or entrapped lubricant in the efrigerant fluid.

The present invention also contemplates an improved heat pump system including a compression cycle, and pump circulation cycle wherein a simple defrosting cycle is established by creating an imaginary load on the come pressor so that the hot vgases of compression will serve to produce effective defrosting of the heat exchanger required.

Accordingly, to provide a simple efficient force feed heat pump with better' heat transfer characteristics due to its ability to provide an increased rate of Circulation of refrigerant lluid whereby the heat exchange surfaces when actingas the evaporator on the maintained wet at all times.

Tt is another object of the present invention to prolow pressure side cycle are vide trained and entrapped in the refrigerant from stratifying in the heat exchangers a single point of oil recovery is necessary.

It is another object of the present invention to provide an improved heat pump wherein a single gas and liquid refrigerant separation device common to both heat exchangers is provided to obtain the required expansion from the high pressure to the low pressure condition.

It is a still further object of the present invention to provide an improved heat pump wherein during these intermediate times of the year where the `operation of the system on a compression cycle is inetlicient that the system can be made to work only on the pumping cycle to provide cooling as may be required.

Further objects and advantages of the invention will become evident from the following description with reference to the accompanying drawings in which:

FIGURE l is a diagrammatic sketch of the invention showing the cooling cycle including an outdoor heat ex'- changer in heat exchange communication with atmospheric air. i

fluid is prevented EGURB 2 is a diagrammatic sketch of the invention it is an object of the present invention an improved heat pump wherein the lubricant enf and wherein only FIGURE 4 is a diagrammatic sketch of the invention showing the intermediate cooling cycle including an outdoor heat exchanger in heat exchange relation with atmospheric air.

FIGURE 5 is a diagrammatic sketch of the invention showing a modied formincluding a superheating means on the suction line into the compressor.

FIGURE 6 is a diagrammatic sketch of the invention showing a modi-tied form of the intermediate cooling cycle including an outdoor heat exchanger in heat exchange relation with atmospheric air.

FIGURE 7 is adiagrammatic sketch of the invention showing a modified form including a low pressure sepa* rating me-ans.

FIGURES 1 to 4 of the drawings illustrate diagrammatically arrangements of the same elements in the form of a heat pump in accordance with the present invention. They are distinguished in that the refrigerant temperature, pressure and ow path between the elements differ for the various cycles cooling, heating, and intermediate.

While in the heat pump system one heat exchanger is shown in heat exchange relation with atmospheric air, it will be understood that such heat exchanger could be associated with other heat sink or heat source media as will 'be understood by those skilled in the art and that the corresponding heat exchanger best for the medium serving las the heat sink or heat source will be utilized.

Furthermore, While the system shows a second heat exchanger in heat exchange relation with circulating water to he heated or cooled, it will be understood that heat exchange can `be with other liquid media or with air or other gaseous media without departing from the scope of the present invention.

General Arrangementof the Heat Pump Thus, referring to FIGURES l to 4 where the same parts will have the ysame characternumerals, a cornpressor is shown at 1 having a discharge outlet 2 connected to a discharge line 3 disposed to receive hot compressed gaseous refrigerant from the compressor. The discharge line 3 is connected to three conduits 4, 5 and 6, each having their respective solenoid operated valves 7, 8 and 9 which can be manually or automatically controlled to provide that direction of iiow in the system which `will Iproduce the desired cooling, heating or defrost cycles hereinafter described:

Conduit 4 communicates with the inlet header it? of a first heat exchanger 1I which will be called for the purpose of the present disclosure the outdoor heat exchanger because it is disposed and located so that atmospheric air can'be passed thereover as by a fan 12 to permit good heat exchange relation to occur between the coils 13 of the heat exchanger and the air. Heat exchangers for this purpose are well known and are easily purchasable on Vthe open market.

-As indicated above, this heat exchanger may for all purposes also lbe one which is adapted for heat exchange relation with other types of heat sink and heat source media.

The outlet 'header 14 -of the first or outdoor heat exchanger communicates through connecting line iS and common conduit 16 with a high pressure iioat regulator 17 in turn connected by connecting conduit 18 to collecting line 19 leading to accumulator 2). High pressure oat regulators and accumulators are elements which arev also well known in the refrigeration art and require no further description.

The accumulator shall be sized sufficiently large to permit a proper separation of the gaseous and liquid refrigerant which is delivered to the accumulator and shalbbe constructed to act as a high pressure receiver for storing the 'entire charge of the refrigerant as may be necessary during shut down periods.

'The compressor has its suction inlet 21 connected as by a suction line Z2 to that portion of the accumulator 2t? occupied by the gaseous refrigerant so that slugging of liquid is avoided during the operation of the compresser.

Conduit 6 communicates with the inlet chamber 23 of the second heat exchanger 24 which is termed for the purposes of the present description as the indoor heat exchanger because it will be disposed at an enclosed point such that either a liquid or gas may be circulated over the coils 2E to provide means for transferring neat or abstracting heat depending on the cycle in operation at the time. This is accomplished in the present form or' the invention by passing liquid through inlet 26 and removing it by outlet 27. Heat exchangers for this purpose are well known in the air conditioning and refrigeration art and are easily purchasable on vthe open market.

The outlet chamber 28 for'the second or indoor heat exchanger 24 is also connected through return line Z9 to the common line 16 which communicates with the high pressure float regulator 17.

FIGURES l to 4 show that the conduits i5 and 29 are provided with check valves as at 30 and 31 respectively so that the flow of refrigerant uid through the outdoor and indoor heat exchangers will be uni-directional, a specific characteristic of the operation of the present invention regardless of the particular cycle in operation.

FIGURES 1 to 4 also show that lines 15 and 29 communicate through lines 32- and 33 respectively directly to collecting line 19 and depending on `the operating cycle which calls for the setting for the control valves 34 and 35 for the respective lines 33 and 32 refrigerant gas and liquid from one or the other vof the heat exchangers 1i or 24 can by-pass the high pressure oat regulator 17 and be passed directly to the accumulator 20.

The operation of the control valves 7, 8, 9, 34 and may be manual or automatic.

Pumping System In order vto provide the positive -or force feeding circulation ot refrigerant 'liquid to the respective indoor andoutdoor heat exchangers in the various cycles vhereinafter described where the heat exchanger is not receiving hot compressed gaseous refrigerant a `pump 40 is provided Vhaving its suction connected by line 4.1 to the portion of the accumulator 2th in which lthe liquid refrigerant settles. The pump discharges through common vdischarge line 42 to the connecting conduits 43a and 44 which are in turn connected to the conduits 4 and 6 leading to the outdoor and indoor heat exchangers 11 and 24.

As shown in FIGURES l to 4 connecting conduits 43 and 44 are provided with check valves 45 and 46 respectively, which check valves will direct the flow of refrigerant liquid depending on the settings of control valves 7 and 9.

Check valves 3G and 31 also operate Vsimilarly depending on the settings of control valves 34 and35.

In both the case of check valves 30 and 31 and check valves 45 and 46 the pressure of the refrigerant will pressurize one or the other .of the check valves so that flow will occur through that check valve which does not have the pressure acting against its discharge side.

The valves 34 and 35 also permit the inclusion of a defrosting cycle which is accomplished through the defrosting conduit 5 connected through valve 8 to the common discharge line 3 and to a point downstream of the solenoid operated valve 7 and the check valve 4S which defrosting cycle is more fully `described hereinafter.

Oil Recovery Means The heat pump with a 'force feed pumping arrangement as above described is lparticularly characterized by the fact that no oil can accumulate in the system in any of the heat exchangers or in any piping traps as occurs in heat pump arrangements now known in the prior art. Gil collects at only a single point in the system, namely the accumulator 2t? and this permits a unique simple method of oil recovery in that oil-rich Freon may be sampled from the downstream side of pump di) by a relatively small bleed line S6 having a solenoid operated valve 5l therein which can be maintained open during these cycles which include compressor operation.

The oil-rich Freon sampled through the bleed line 4d is evaporated by wrapping the bleed line as at 52 about one of the hot lines such as the discharge line 3 from the compressor. This evaporated refrigerant in gaseous form containing small particles of oil can be returned to the compressor by connecting the outlet of line 50 to the suction inlet line 22. leading to the suction of the compressor Since there is a pressure ditference between the discharge side of the pump 4u and the suction side of the compressor ll, a very effective non-clogging, easily regulated oil recovery system will be incorporated in the heat pump. A control for sensing superheat in line Sti' is provided as at S3 and will be utilized to regulate the iiow of oil-rich Freon through line 5l).

Figure 5-Modied Form of the Invention With Superheating FIGURE 5 shows a modified form of the invention wherein means is provided for superheating the gaseous refrigerant before it is passed into the compressor suction so as to insure against moist gas entering the compressor and further to increase the differential of temperature across the compressor.

ln FIGURE 5 identical elements have been given the same character numerals and as shown the modification to produce the above results consists in merely changing the line leading to the high pressure iloat regulator 17.

Thus line llo connected at one end to the respective lines l5 and 29 and at the other end to the high pressure float regulator Tt? has its intermediate portion coiled as at 55 about the suction line 22.

ln operation as the compressor 1 draws gaseous refrigerant from the accumulator 2d through line 22 the gaseous refrigerant comes into non-contacting heat exchange relation with the hot liquid refrigerant passing through coil 5S of line 1d. The hot liquid refrigerant superheats the gaseous refrigerant passing through suction line 22, thereby evaporating any particles of liquid refrigerant entrained in or carried by the gas being passed to the compressor, thus insuring against any possibility of slugging that might cause damage to the compresser.

The operating cycles of this modified form of the invention is otherwise identical with those hereinafter described for the form of the invention shown in FlG- UlES l to 4.

Figure 7-M0di,fzed Form of Invention With Low Pressure Separation Means in the above described heat pump only a preferred form of the invention is illustrated and this shows the use of a high pressure actuated separating means to separate the hot compressed gaseous refrigerant from the cold low pressure refrigerant liquid.

his separation of gas and liquid can also be accomplished by means of a low pressure actuated arrangement such as is shown in FIGURE 7 of the drawings. Thus, in FlGUlll 7 identical elements have been given the same character numerals, and as shown the modification line llo now leads to a high pressure type receiver e@ which in turn is connected to the accumulator through a feed line 6i. -lilo-w of refrigerant liquid through the line el is regulated by control valve 6.2 which is actuated in response to signals from the level controller d3. Level controllers with means to deliver electrical or pneumatic signals to the control valve e?, are well known in the control art and their operation for the purpose shown in the drawing is also understood and therefore will not be described more fully.

The above described heat pumps as shown in FIG- URES l, 5 and 7 can be operated so to include a con pression cycle or without a compression cycle. When the system is operated with compression the equivalent cooling and heating cycles of conventional heat pumps can be obtained. When the system is operated without compression the valves are so positioned that the pump can force or positively feed refrigerant liquid to the respective heat exchangers in parallel or in series and the heat exchangers will return the liquid to a mixing source so that cooling can be obtained.

These various operating cycles of the heat pump system will now be more fully described, and reference is provided on the figure described for approximate temperature, pressure conditions and for the physical state of the refrigerant at given points in the cycle.

The valves other than check valves will be regulated to their open, closed or modulated positions either manually or automatically.

Cooling Cycle Cooling of a liquid or gaseous media in heat exchange relation with the indoor heat exchanger 2d can be obtained by operating the heat pump in the following manner:

First, the compressor l, the pump iti and the fan 12 are placed into operation. Valves 7, 3d and 5l will be open and all other valves will be closed. Hot compressed gaseous refrigerant from compressor li will pass through the discharge outlet 2 and common discharge line It to the conduit l connected to the inlet header it? of' outdoor heat exchanger lll. in the outdoor heat exchanger il?. the hot compressed gaseous refrigerant will be condensed to provide a hot liquid refrigerant which will collect in the outlet header Std of the outdoor heat exchanger il.

The hot liquid refrigerant passes from the outlet header 1d through lines l5 and 16 to the high pressure float regulator E7 which serves to pass or meter liquid of which a portion flashes into gas through lines lit and 19 to the accumulator 2t?. This mixture of relatively cold gas and liquid refrigerant mixes with other relatively cold gas and liquid refrigerant which is returned from the indoor heat exchanger as hereinafter described.

In the accumulator 2u which is properly sized, the gaseous and liquid refrigerant separate so that a gas layer occupies the upper portion of the accumulator and the liquid layer occupies the lower portion of the accumulator, as is indicated by the dotted line in FIGURES 1 to 4.

Since the suction line 2 of the compressor is connected to the upper portion of the accumulator which holds the gaseous refrigerant only gas passes through the suction line 22 and the suction inlet 21 of the compressor where it is once again recompressed to repeat the con- (lensing cycle.

The relatively cold liquid refrigerant in the accumulator 2li is also pumped with positive pressure to the indoor heat exchanger 2d by means of the pumping system` above described. Thus pump ed receives liquid through the line 4l and discharges the refrigerant liquid through line Due to the fact that hot compressed gaseous refrigerant is passing through conduit 4 the check valve 45 is prevented from opening and this discharged liquid refrigerant under pressure must be delivered through conduit 44 and check valve d5 to the conduit 6 connected to the inlet header 23 of the indoor heat exchanger Zd.

At the indoor heat exchanger the liquid refrigerant is passed therethrough into heat exchange relation with fluid which is delivered through line Z6 ruid removed by line 2.7 so that the cold liquid refrifferant is heated as it cools the fluid being passed through the indoor heat exchanger. This cooled fluid media as it leaves line 2'7 may be passed to any suitable point of use.

It is believed clear to those skilled in the air conditionaser/,oss

7 ing and refrigeration art that air or other gaseous media could also be cooled by passing in heat exchange relation with a suitable type indoor heat exchanger without departing from the scope of this invention.

The refrigerant collected in the outlet header 28 of heat exchanger 24 will be part gas and part liquid because the pump supplies a greater quantity of liquid than is required for the capacity of the heat exchanger, This is advantageous because the inner surface of the tubes of the heat exchanger will under these conditions be continually wetted thereby increasing the eiliciency of the heat exchanger.

This mixture of gaseous and liquid refrigerant will be passed from the outlet header 2S through lines 29, 32 and control valve 34 to the collecting line 19 where it joins with a like mixture of gas and liquid from the high pressure float regulator 17 as it ows through line 1% to the accumulator 2G connected thereto.

This pumping circulation cycle will operate continuously to provide the desired cooling as long as the compressoi continues to operate with the valves eet for the cooling cycle as above described.

Heating Cycle In the heating cycle shown inFlGURE 2 the compressor 1, the pump 40 and the fan 12 are first placed into operation. All valves are closed except control valves 9, 35 and 51.

Hot compressed gaseous refrigerantwill be discharged from the compressor through discharge outlet 2 and dis* charge line 3 to conduit 6 and will be passed by conduit 6to the inlet header 23 of the indoor heat exchanger 24 where it gives up heat to the medium to be heated, as for example, water brought into the heat exchanger 24 through inlet 26 and discharged to the desired point of use through outlet 27 in the heated condition. lt is understood that heat exchange could be made with other liquid media-or air or other gaseous media without departing fromtheseope of this invention, and that'where air or a gas media is used that the type heat exchanger required for this media will also be used as is well known in the heat pump art.

AThe release of heat to the media to be heated causes the gas to condense to provide liquid refrigerant, which liquidrefrigerant passes through the outlet header 28 of theheatexchanger 24 through line 29 and check valve 3 1 to the common line 16 leading into the high pressure float regulator 17.

In high pressure float regulator 17 the liquid 'ashcs and during the expansion cools so that relatively cool gas and liquid refrigerant is then led to the accumulator 2d through line 19. This mixture of relatively cold gas and liquid refrigerant similar to the cooling cycle mixes with o ther relatively cold gas and liquid refrigerant which is returned from the indoor heat exchanger as hereinafter described. By reason of thev sizeof the accumulator Ztl the refrigerant mixture separates to provide a gaseous layer and-a liquid layer of the refrigerant in intimate contact with'each other.

Since the suction line 22 communicates with the gaseous portion of the refrigerant in the accumulator the compressor `will draw gaseous refrigerant through the suction inlet line 22 and suction inlet 21 into the compressor where it will be recompressed to pass through the cycle above described.

In addition to the heat of compression heat is also drawn from the heat source in contact with the outdoor heat exchanger 11 by force feeding refrigerant liquid to the outdoor heat exchanger. This is accomplished by means lof the pumping assembly. Thus pump 40 through line 41 draws cold liquid refrigerant from the liquid layer of the refrigerant in the accumulator 2li and discharges it through discharge line 42. Since hot compressed gaseous refrigerant is being discharged through conduit 6 the pumped fluid cannot pass through the check v-alve 46 and instead passes through check valve 45 in conduit 43 into conduit 4 connected thereto where it is forced to the inlet header 10 of the outdoor heat exchanger 11. As it passes through coils 13 of the outdoor heat exchanger 11 the liquid refrigerant which will always be colder than the heat source will pick up heat from the heat source and then from the outlet header 14 it will be passed through lines 15, line 33, and control valve 35 to collecting line 19 and thence to the accumulator 20 where it mixes with the mixture of gas and liquid refrigerant returning from the high pressure float regulator 17 to the accumulator 26,'. The mixtures passed to the accumulator separate and as above described recirculate through lines 22 and l1 to the compressor and pump respectively, to repeat the cycle.

Defrost Cycle When the heating cycle is in operation and an outside heat exchanger is used in non-contacting heat exchange relation with air as has been above described, it is known that ice or frost will collect on the outside surface of the coils of the outdoor heat exchanger. As this coating of ice or frost increases, the efficiency of the outdoor heat exchanger will reduce and accordingly it is necessary to provide a mechanism for removing this ice or frost. This is accomplished in the present invention -by means of a simple defrost cycle.

The defrost cycle is characterized by the fact that the compressor is artificially loaded, and operates to iow hot lgas as the heat carrying medium through the system in a non-condensing cycle. This is accomplished by inserting the equivalent of an orifice in the ow path across which the compressor moves the defrosting fluid. In actual operation this orifice is eiective by constricting the control valve to accomplish this result.

Thus as shown in vFIGURE 3 compressor 1 is placed in operation. Fan 12 and pump all are not put in operation. All valves will be closed except control valves-8 and 35. As the compressor operates hot compressed gaseous refrigerant is discharged through the discharge outlet 2 and discharge line 3 to `t-he defrostconduit 5 which has the control valve 8 therein. As indicated in FIGURE 3 the hot compressed gaseous refrigerant will as it passes through the control valve 8 reduce the pressure from l250 p.s.i.g. to 50 p.s.i.g. so that the gas on the downstream side of the control valve S is superheated gas at the temperature and pressure indicate-d. This hot superheated gas is passed to conduit 4 land thence to the inlet header 10 of the heat exchanger 11.

Since the fan 12 is not in operation the hot compressed gaseous refrigerant will deliver the bulk of its heat to the walls of the coils thereby melting the encrusted ice and frost on the outer surface of the coils and the cooled gaseous refrigerant collected in the outlet header 14 will then be returned by differential pressure through lines 15, 33, control valve 35 and line 19 to the accumulator 2t) which circuit merely serves to return the cooled gaseous refrigerant back to the ycompressor through suction line 2 2 and suction inlet 21. The `,cycle will be repeated until the heat exchanger is completely free of ice or frost and this should be accomplished in approximately 15 to 20 minutes so as to permit the heating cycle to be continued without an excessive length of interruption.

The effect of the restriction in the defrost flow cycle is to impose the artificial load on the compressor. lf the compressor did not operate with such a load very little heat would be generated. However, with this heat load imposed the compressor must do work in lifting the gas from 50 to 250 pounds which work is transmitted into heat carried by the gas and this heat is utilized to defrost the outdoor coil of the heat exchanger 11 very rapidly. Thus capacity is not robbed from the media previously heated nor is heat drawn-from the very space of system which the heat pump is required to supply heat to. Furthermore, no additional equipment or other means such as hot water sprays, electric resistance heaters or blankets are required.

The heat utilized for the defrost cycle in the present invention is obtained by direct conversion of the electrical input into the compressor motor into heat which is carried by the gaseous refrigerant circulated through the system.

Intermediate Cooling Cycle ln the intermediate cooling cycle cooling is effected by a mixing process where the heat content of two portions of the refrigerant is changed by circulating it through the respective heat exchangers. t

One portion can discharge heat to the heat sink, the other can absorb heat from the media to be cooled and the respective portions can then be remixed together for recirculation through the system once again.

This operating cycle is designed for limited conditions where some but not a large quantity of cooling is required. Furthermore the circulation can be either in parallel as shown in FGURE 4 or in series as shown in FlGURE 6 and these respective operating cycles will not be described.

Thus by reference to FlGURE 4 We iind in this cycle that only the pump itl and fan l2 will be in operation. The compressor will not be in operation. In addition, valves 7, il, 9 and il will be closed and valves 34 and 35' will be open.

ln operation pump 4d draws refrigerant liquid from the accumulator El) and discharges the liquid under pressure through line d2 and through connecting conduits i3 and 4d simultaneously into conduits 4 and 6 respectively, which in turn direct the liquid refrigerant to the inlet header lil for the heat exchanger ll and inlet header Z3 for the heat exchanger 24.

Refriserant liquid in heat exchanger l1 will pass through the coils lli in non-contacting heat relation with air passed thereacross by the fan l2 and will be cooled. rlhe cooled refrigerant collects in the outlet header ld and is passed via lines l5, 33 and collecting line 19' to the accumulator ld.

Similarly, liquid refrigerant in heat exchanger 24 will pass through its coils in non-contacting heat exchange relation with the media, be it liquid or gas or other lluid to be cooled, as for example, water which is introduced through inlet 26 and discharged through outlet 27 of the heat exchanger which cooled liquid can be utilized for cooling at any suitable point.

The heat exchange relation passes a mixture of gas and liquid refrigerant to the outlet header 23 of the heat exchanger which mixture llows via lines 32, control valve 34- and collecting line i9 to the accumulator 2d where it mixes with the cooled liquid refrigerant returning from the heat exchanger ll. Mixture of the two provides a liquid refrigerant having an ambient temperature which will once again permit it to absorb heat from the media to be cooled by repetition of the flow cycle above described.

Where the intermediate cooling cycle is accomplished by series flow, the system must be modiled as shown in FEGURE 6.

This is done by providing a connecting line at du to connec` the outlet header Z5 of heat exchanger 2d to couduit d, and inserting a solenoid operated control 6l, valves in line 6G and replacing the check valves in lines 29 and d3 with solenoid valves as at d2 and 63.

During operation of this modified system only the pump itl and fan l2 will be in operation. Once again, the compressor will not be in operation. Valves 7, 8, 9, Se, Ell, d2, 63 will be closed and valves 6l and 35 will be open.

`Pump d@ will draw cold liquid refrigerant from the accumulator Ztl and discharge this liquid through lines d?. and and conduit 6 into the inlet header Z3 of the heat exchanger Zd. The liquid refrigerant will give up heat to the water circulated through the heat exchanger through inlet 2o and outlet 27 and will as a result of the heat exchange relation be converted into a mixture of gas and liquid refrigerant which collects in the outlet header 28 of the heat exchanger 2d. The mixture of gas and liquid refrigerant is passed from the outlet header 2li via connecting line eil and conduit t to the inlet header lll of the outdoor heat exchanger ll where the refrigerant is cooled by heat exchange relation with air passed over the coils i3 of the heat exchanger lli-i, thereby condensing the gaseous portion of the refrigerant. The now liquid refrigerant collects in the outlet header ld and is passed by lines l5, 33 and 19 to the accumulator :Ztl connected by line 4l to the pump itl which permits this cycle to repeat itself as long as the pump ttl and fan i2 continue to operate.

lt will be understood that the invention is not to be Ylimited to the specific construction or arrangement of parts shown but that they may be widely modied within the invention defined by the claims.

What is claimed is:

l. In a heat pump, a plurality of heat exchange means, a common separating means for storing and separating gaseous and liquid refrigerant, means connecting the downstream side of each of said heat exchange means to said separating means, a compression means, said compression means having its suction connected to said conmon separating means, conduit means communicating the discharge of said compression means to the upstream side of said heat exchange means, said conduit means being adapted to deliver hot compressed gaseous refrigerant interchangeably and selectively to the upstream side of at least one of said heat exchange means, and a pump circulation cycle having its suction connected to said separating means to receive liquid refrigerant therefrom and to force feed an excess of liquid refrigerant to the upstream side of at least one other of said heat exchange means not receiving hot compressed gaseous refrigerant from said compression means.

2. In a heat pump, a first heat exchange means and a second heat exchange means each having inlet means and outlet means, at least one compressing means, at least one pumping means, means to interchangeably and selectively connect the compressing means and the pumping means to he respective inlet means for the first and second heat exchange means, a common separating means for storing and separating gaseous and liquid refrigerant, means connecting the respective outlet means for said first and said second heat exchange means to the common separating means, said compression means having its suction connected to said common separating means to receive gaseous refrigerant therefrom and to pass hot compressed gaseous refrigerant to that heat exchange means selectively connected to the discharge of the compression means, and said pumping means having its suction connected to said common separating means to receive liquid refrigerant therefrom and to pass an excess of liquid refrigerant under pressure to that heat exchanger means selectively connected to the discharge of the pumping means.

3. ln the heat pump as claimed in claim 2, an oil recovery means including, line means connected between the discharge side of said pumping means and the suction side of the compression means for bypassing a predetermined quantity of mixed oil and liquid refrigerant, and means in said line means for superheating the mixed oil and liquid refrigerant whereby a vaporized mixture of oil and gas refrigerant is passed to said suction side of the compressor.

4. In the heat pump as claimed in claim 3 wherein said superheating means comprises, a cooling coil formed in said line means, said cooling coil mounted at .any suitable point in the heat pump for non-contacting heat exchange relation with means carrying said hot gaseous refrigerant.

5. In the heat pump as claimed in claim 2 wherein means connected between the separating means and the spaanse suction of the compression means acts to superheat gaseous refrigerant passing from the separating means to the suction of the compressor.

6. ln the heat pump as claimed in claim 2 wherein a return line provides means for connecting the suction of the compressor to the separation means for passing the gaseous refrigerant from the separation means to the suction inlet of the compressor, and means connecting the downstream side of the heat exchange means to the separation means. operatively connected to said return line for super-heating the gaseous refrigerant passing to said compression means.

7. In a heat pump, a rst heat exchange means and a second heat exchange means each having inlet means and outlet means, at least one compressing means, at least one pumping means, means to interchangeably and selectively connect the compressing means and the pumping means tothe respective inlet means for the first and second heat exchange means, a common separating means for storing and separating gaseous and liquid refrigerant including, a iiow regulating means to meter the high pressure mixture of gaseous and liquid refrigerant therethrough, an accumulator means operatively associated with said flow regulating means, means connecting the outlet means of the heat exchange means selectively connected to receive hot compressed gaseous refrigerant to the flow regulating means, means connecting the outlet means of that heat exchange means selectively connected to thek pumping means to `the accumulator means, said compression means having its, suction connected to said common separating means to. receive gaseous refrigerant therefrom and to pass hot compressed gaseous refrigerant to that heat exchange means selectively connected to the discharge of the compression means, and said pumping means having its suction connected tosaid common separating means to receive liquid refrigerant therefrom and to pass an excess of liquid refrigerant under pressure to that heat exchanger means selectively connected to the discharge of the pumping means. Y

8,. In the heat pump as claimed in claim 7 wherein said regulating means comprises, a high pressure float regulator having an inlet and an outlet, said inlet connected to the outlet of that heat exchanger selectivelyv connected to receive hot compressed gaseous refrigerant, and said outet for the iloat regulator connected to the accumulator to pass the dashed mixture of gaseous and liquid refrigerant thereto.

` 9. In the heat pump as claimed in claim 7 wherein said regulator means comprises, a high pressure receiver, said receiver having an inlet and an outlet the inlet of said receiver connected to the outlet means of the heat exchange means selectively connected to receive hot compressed gaseous refrigerant, conduit means connecting the outlet of said high pressure receiver to the accumulator, a control valve means in said conduit for regulating ovv of refrigerant from said receiver Lo said accumulator, a liquid level control means on said accumulator, and means connecting said liquid level control means tol said control valve means ,to automatically regulate operation of the control valve in accordance with variations of the level of liquid refrigerant in said accumulator from the desired predetermined level.

li). ln a heat pump, a iirst heat exchange means and a second heat exchange means each having inlet means and outlet means, at least one compressing means, at least one pumping means, means to interchangeably and selectively connect the compressing means and the pumping means to the respective inlet means for the first and second heat exchange means, a common separating means for storing and separating gaseous and liquid refrigerant, means connecting the respective outlet means for said first and said second heat exchange means to the common separating means, said compression means having its suction connected to said separating means to receive gaseous refrigerant therefrom and to pass hot compressed gaseous refrigerant to that heat exchange means selectively connected to the discharge of the compression means, and said pumping means having its suction connected to said common separating means to receive liquid refrigerant therefrom and to pass an excess of liquid refrigerant to that heat exchanger means selectively connected to the discharge of the pumping means and not receiving hot compressed gaseous refrigerant from said compressor whereby the pumping means Will coact with said compressing means during the cooling and heating cycles; and said pumping means adapted to operate independently of the compressing means to deliver an excess of relatively cold refrigerant from the common separating means to the inlet of each of said first and second heat exchange means in parallel and in series during the intermediate cooling cycles.

ll. In a heat pump having cooling, heating and intermediate cooling cycles, a high pressure side cycle including, compression means and at least one heat exchange means, a loW pressure side cycle including, pump means, and at least one other heat exchange means, means to interchangeably and selectively deliver hot compressed gaseous refrigerant from said compression means to the upstream side of said first mentioned heat exchange means and to the upstream side of said second heat exchange means to permit said heat exchange means to function interchangeably, means to interchangeably and selectively feed cold liquid refrigerant from said pump means to the upstream side of said first mentioned heat exchange means and to the upstream side of said second heat exchange means when the respective heat exchange means is not connected to receive hot gaseous refrigerant from said compression means, a common separating means for storing and separating gaseous and liquid refrigerant, means connecting the downstream side of said lirst heat exchange means and said second heat exchange means to said common separating means, said compression means having its suction inlet connected to said common separating mean-s and its ldischarge outlet connected to said means for interchangeably and selectively delivering hot compressed gaseous refrigerant to the upstream side of the respective first and second heat exchange means, and said pump means having its suction connected to said common separating means and its discharge connected to said means for delivering cold liquid refrigerant to said first and said second heat exchange means and at all times to deliver an excess of liquid refrigerant to the respective heat exchange means connected thereto for the particular cycle of operation.

l2. In a heat pump having cooling, heating and intermediate cocling cycles, a high pressure side condensing cycle including, a first heat exchanger having an inlet and an outlet, a second heat exchanger having an inlet and an outlet, a compressor, means to interchangeablyy and selectively connect the discharge of said compressor to the inlet side of the respective rst and second heat exchangers to permit said first heat exchanger and Vsaid second'heat exchanger to function interchangeably, a common separating means for storing and separating gaseous and liquid refrigerant, means connecting the respective outlet side of said rst and second heat exchanger to said separating means, and said compressor having its suction connected to said separating means to receive gaseous refrigerant therefrom and to deliver hot compressed gaseous refrigerant through said means to the selected heat exchanger, and a circulation cycle having -a pump therein connected to receive liquid refrigerant from said separating means and during the heating and cooling cycle to coact with the compressor for delivering relatively cold refrigerant under pressure from the separating means to the inlet of that heat exchanger not receiving hot compressed gaseous refrigerant, and said circulation cycle disposed to operate independently of the compressor to selectively deliver relatively cold liquid refrigerant from the separating means to the respective heat exchangers for selective parallel and series operation on the intermediate cycle.

13. In a heat pump having cooling, heating and intermediate cooling cycles, a high pressure side cycle including, compression means and at least one heat exchange means, a low pressure side cycle including, pump means, and at least one other heat exchange means, means to interchangeably and selectively deliver hot compressed gaseous refrigerant from said compression means to the upstream side of said first mentioned heat exchange means and to the upstream side of said second heat exchange means to permit said heat exchange means to function interchangeably, means to interchangeably and selectively feed cold liquid refrigerant from said pump means to the upstream side of said first mentioned heat exchange means and to the upstream side of said second heat exchange means when the respective heat exchange means is not connected to receive hot gaseous refrigerant from said compression means, a common separating means for storing and separating gaseous and liquid refrigerant, means connecting the downstream side of said first heat exchange means and said second heat exchange means to said common separating means, said compression means having its suction inlet connected to said common separating means and its outlet connected to said means for interchangeably and selectively delivering hot compressed gaseous refrig erant to the upstream side of the respective first and second heat exchange means, and said pump means having its suction connected to said common separating means to receive liquid refrigerant from said separating means and during the heating 4and cooling cycle to coact with the compressor for delivering relatively cold refrigerant under pressure from the separating means to the inlet of that heat exchanger not receiving hot compressed gaseous refrigerant; and said pump means disposed to operate independently and without the compressor to selectively deliver relatively cold liquid refrigerant from the separating means to the respective heat exchangers during the inter mediate cycle.

14. In the heat pump as claimed in claim 11, an oil recovery means including, line means connected between the discharge side of said pumping means and the suction side of the compression means for bypassing a predetermined quantity of mixed oil and liquid refrigerant, and means in said line means for superheating the mixed oil and liquid refrigerant whereby a vaporized mixture of oil and gas refrigerant is passed to said suction side of the compressor.

15. In the heat pump -as claimed in claim 11 wherein means connected betwen the separating means and the 14 suction of the compression means acts to superheat gaseous refrigerant passing from the separating means to the suction of the compressor.

16. In the heat pump as claimed in claim 2, a defrost means comprising, a defrost line connecting the discharge of said compression means to the inlet for that heat exchanger means to be defrosted, restriction means in said defrost line, said defrost line and means for interchangeably and selectively connecting the compression means and the pump means to the respective heat exchanger adapted to permit free flow of gaseous refrigerant to and from the heat exchange means to be defrosted whereby the compression means is loaded due to the work of forcing the gaseous refrigerant through said restriction means.

17. In a heat pump having at least one heat exchange means in communication with a heat sink and heat source media, compression means, conduit means connecting the discharge outlet of said compressor to the upstream side of said heat exchange means, valve means in said conduit to be closed during defrosting of the heat exchange means, separating means for storing and separating gaseous and liquid refrigerant, means connecting the downstream side of said heat exchanger to the separating means, and means connecting the suction of said compression means to the separating means to draw gaseous refrigerant therefrom, the combination therewith of a defrost cycle including, a conduit connected to the discharge of said compression means and to said conduit means downstream of the valve means to permit hot compressed refrigerant to be directed from the compressor to the inlet of said heat exchange means, Valve means to selectively control flow through said defrost conduit, and means forming a restriction in said defrost conduit to force said compressor to perform work when the defrost conduit valve is open for defrosting.

References Cited in the tile of this patent UNITED STATES PATENTS 1,703,965 Shipley Mar. 5, 1929 2,140,462 Stratford Dec. 13, 1938 2,185,515 Neeson Jan. 2, 1940 2,225,491 Vorhees Dec. 17, 1940 2,344,215 Soling Mar. 14, 1944 2,617,265 Ruff Nov. 11, 1952 2,715,317 Rhodes Aug. 16, 1955 2,718,764 Kramer Sept. 27, 1955 2,718,766 Imperatore Sept. 27, 1955 2,779,171 Lindenblad Jan. 29, 1957 2,882,698 Boyle Apr. 25, 1959 2,892,321 Kritzer June 30, 1959 

1. IN A HEAT PUMP, A PLURALITY OF HEAT EXCHANGE MEANS, A COMMON SEPARATING MEANS FOR STORING AND SEPARATING GASEOUS AND LIQUID REFRIGERANT, MEANS CONNECTING THE DOWNSTREAM SIDE OF EACH OF SAID HEAT EXCHANGE MEANS TO SAID SEPARATING MEANS, A COMPRESSION MEANS, SAID COMPRESSION MEANS HAVING ITS SUCTION CONNECTED TO SAID COMMON SEPARATING MEANS, CONDUIT MEANS COMMUNICATING THE DISCHARGE OF SAID COMPRESSION MEANS TO THE UPSTREAM SIDE OF SAID HEAT EXCHANGE MEANS, SAID CONDUIT MEANS BEING ADAPTED TO DELIVER HOT COMPRESSED GASEOUS REFRIGERANT INTERCHANGEABLY AND SELECTIVELY TO THE UPSTREAM SIDE OF AT LEAST ONE OF SAID HEAT EXCHANGE MEANS, AND A PUMP CIRCULATION CYCLE HAVING ITS SUCTION CONNECTED TO SAID SEPARATING MEANS TO RECEIVE LIQUID REFRIGERANT THEREFROM 